Personally, I haven't particularly noticed any speed increase because I used a 64-bit OS. I have had both FreeBSD and OpenBSD in 32-bit and 64-bit environments, but the only speed increase I have seen is through an SMP-enabled kernel and some other things like better graphics cards or more memory.

Just because the system is 64-bit doesn't mean it will be any faster; it's more of a programming issue. Really, all that 64-bit hardware gives you is a larger addressing space. It could possibly mean more speed if 64-bit addressing removes some bottleneck in a particular application (this really helps in high performance computing and large servers), but in general, there probably isn't much of a difference when comparing an AMD64 desktop to a standard x86 PC.

__________________"Experience is what you get when you were expecting something else." - /usr/games/fortune

I know, it's off topic, but it did come up. Here's my take on 32 vs. 64 for workstations:

The biggest benefit of 64-bit over 32-bit in a general purpose workstation environment is memory addressing improvement, the most obvious of which is being able to address more than 4GB of RAM. There are possible data transfer improvements between registers, cache, and RAM, but only if if the particular hardware being used can exploit them. There are some less obvious but helpful addressing benifits, particularly in virtual storage management. For 64-bit OSes which can run 32-bit binaries, using so-called 64-bit applications instead of 32-bit means that the application may be able to take advantage of the wider data paths, and may improve their CPU performance.

As to the comparison of various OSes and their performance, I'm not sure you'll get useful info from most of us. Since those of us who multiboot workstations do so primarily to exploit different applications, the performance mix will not be the same. You'll have to be lucky and find someone who happens to run the same app on multiple OSes for some reason.

Example:

I have three OSes on my 32-bit laptop, each used regularly for different applications: OpenBSD, Ubuntu, and W2K.

On my 64-bit laptop, I use three OSes: WXP, OpenBSD/i386, and OpenBSD/amd64. OpenBSD is booted from USB drive on this platform. The workloads are entirely different, WXP is for office automation and BSD is for compiling systems and ports, and testing, so there's really no way to make any kind of rational perception comparison, even if I/O were not a factor.

In order to do any kind a comparison you have to run identical hardware, identical applications, and to have things identically configured.
My ThinkPad 390E (PII) with CPU 333MHz and 256Mb of PC100 RAM is very responsive Desktop system probably due to the fact that I run only X server with CWM and use mostly command line applications. The OS is OpenBSD 4.4. i386. I would guess that NetBSD should be little bit faster since it uses XFree86 and uses less cryptography and randomization. I would also assume that
FreeBSD is little bit slower since it is optimized for multi CPUs and much better hardware. Simply FreeBSD just need little bit more RAM to run optimally. Can you really notice the difference. Probably if you really want to notice them but otherwise are insignificant.
You are more likely then not to be penalized in speed for using AMD64 because most
desktop applications are coded for 32 bit OS. That said, I personally do run AMD64 OpenBSD on this very workstation from which I am writing you the letter because
I have 2 cores and 3 Gb of RAM.

Now if I was running MySQL on server with 8 cores and 16Gb of RAM my hunch would be that FreeBSD would significantly out preform at least OpenBSD.

The 4GB memory limit is becoming very real, memory is so cheap nowadays it's almost a crime not to put a gigabytes of it in a new system, you can get 2GB modules for ~35EUR, so the 4GB limit is reached very fast nowadays, even for normal desktop PCs.

__________________
UNIX was not designed to stop you from doing stupid things, because that would also stop you from doing clever things.

I just posted this on freebsd forums. I think there is a big difference even between the same OS on the same hardware depending on the OS architecture.

Hi,

I've been using all of the major BSD off and on for about 3 or 4 years. I just got some new boxes and needed a good desktop so I tried all the latest releases and I just about settled on FreeBSD AMD64 for this machine but after using it for a full day the performance feels really bad.

I know that saying the performance feels bad doesn't mean much so I ran some programs to try to quantify it.

I used rarcrack to brute force passwords against a rar archive with a long password. To me it's a good example of CPU throughput that doesn't use much memory. On a really slow Linux on the same box (openSUSE 11.1) I can test about 750 passwords per second. On the same archive on the same box running FreeBSD AMD64 it only processes 22 passwords a second. I don't understand how this can be happening.

According to the list published on phystech these numbers look pretty good. But the system feels extremely sluggish (applications take forever to load) and there are other performance problems. Most of my downloads building ports die in the middle, it took me ages to get things built.

I don't have much disk space left on this box but I left a primary partition on one of the drives so I may try to install i386 again run ubench on that arch to see if it makes any difference.

The 4GB memory limit is becoming very real, memory is so cheap nowadays it's almost a crime not to put a gigabytes of it in a new system, you can get 2GB modules for ~35EUR, so the 4GB limit is reached very fast nowadays, even for normal desktop PCs.

That is very interesting information. In U.S. where I live you can get
2x1Gb for less than $20 which is about 15 Euros if I am not mistaken.
Recently, I put down the cost for building server with 2x4 cores (two processors per mother board of course), 16Gb RAM and 3x500Gb SATA hard drives. It came to about $1400. Since Opterions with 4 cores are still relatively expensive just by putting 2x2cores will bring the server under $1000. That is just incredible. For curios good starting point for parts shopping in U.S. is newegg.com.